Prior art classical stringed musical instruments in the violin family (refer to the "stick" drawing of FIG. 1) utilize a set of strings 10, 12, generally four in number, which are strung from tuning pins 14 in neck 16 of the instrument, over bridge 18 set on belly 20, back to tailpiece 22 which is held in place by tail block 24 and tail pin 42 of the instrument. Below the right bridge foot (not shown in FIG. 1, but see, FIG. 5 at reference numeral 26) a sound post 28 is placed, essentially between belly 20 and back 30 of the instrument, but slightly behind the right bridge foot, as shown. It is and has been believed that this location provides optimum coupling of sound vibrations from belly 20 to back 30 of the instrument and thereby provides for sympathetic vibration between the two plates when the strings are excited by a bow or fingers.
I have published a paper on the subject "The Violin Sound Post as a Phase Regulator," Journal of the Violin Society of America, Vol. VII, No. 4, pp. 122-133, Queens College Press, which describes in some detail the research I have done on this subject and the conclusions at which I have arrived.
A study of publications in this area indicate that string players and composers have contained to seek stringed instruments in the violin family which exhibit optimum dynamic range and sensitivity; a trend which began about three hundred years ago. Over the years, in order to get more brilliance and volume from the stringed instrument sections of the orchestra, standard pitch has been gradually raised more than two semitones by increasing tension in the strings and by introducing metal strings, both of which are now in common use. Also, violin bridges have been increased in height.
These factors, both separately and in concert, create much greater pressures which are applied to the belly of the instrument through the bridge. The increase in pitch, alone, has caused this pressure to increase by fifty percent or more over the period of development of the instruments. In older instruments, such as those of Stradivarius, Guarnerius and others of the Cremonese school, the belly and back thicknesses were considered to be optimum, and are still so considered and are commonly employed in modern instruments. But because of the factors identified above, much higher pressures are now applied to the belly and back plates than they were originally designed to accommodate. As a partial solution to this increase in pressure over the years, bass bars have been modified to much stronger, heavier construction. While this accomodates the increased pressure on the belly, it adds mass and stiffness to the instrument, thus adversely affecting the resonant characteristics thereof. This practice also tends to inhibit the free vibration of the belly.
In conventional prior art violin construction (see, FIG. 1), the vertical angles between bridge 18 and strings 10, 12, forward and to the rear of bridge 18, respectively, are asymetrical; the angle 38 forward of bridge 18 being somewhat larger than angle 36 on the rearward side of bridge 18. It is believed that because of the imbalance in angles 36, 38, sound post 28 must be optimally located slightly to the rear of the right bridge foot 26 so that it may properly function as a phase regulator between back 30 and belly 20; so that back plate 30 vibrates in synchronism with the major portion of belly 20 which is affixed to the bass bar (not shown in FIG. 1, but see, FIGS. 3, 4 and 5 at reference numeral 32). This optimal configuration has been determined empirically over centuries of experience with such stringed instruments and it has been shown that, given the conventional designs in use, such configuration provides for best communication of sound vibration from belly 20 to back plate 30.
However, the indirect path of such vibration communication required by the classic configuration is not efficient because of the offset (rearward) location of the sound post. Sound energy is thus forced to travel a somewhat torturous path to back plate 30.